JP3074183B2 - Information recording medium and information recording medium evaluation device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to an information recording medium such as an optical disk or a magnetic disk, and an evaluation device therefor.

[Conventional technology]

Information recording media such as optical disks and magnetic disks are formed by laminating a recording layer on the surface of a substrate by, for example, a vacuum film forming method such as a sputtering method or a vacuum evaporation method. It is practically difficult to form a film, and it is more common to have a defect in a part of the recording layer.

If the defect is a large defect as found by visual inspection, the information recording medium is treated as a defective product on the production line. On the other hand, if the defect is a small defect that cannot be found by visual inspection, for example, a pinhole, the location of the defect is registered in the information recording medium itself and the recording area including the defect is recorded. Is made unavailable in advance, and the remaining portion can be used effectively.

FIG. 5 is an explanatory view showing a conventionally known example of zone division of an optical disc. When an information recording / reproducing operation such as recording / reproducing characteristics of the optical disc is performed from the inner peripheral side, a drive and a drive are performed. A first management zone 1 in which data required by the controller, data recorded by the producer for quality control, and the like, a user zone 2 used by a user for recording / reproduction of information, Management zone 3 in which data substantially similar to the management information of
And is divided into: Further, the user zone includes, from the inner side, a first index area 4 in which initial defect data before starting to be used is registered, a user area 5 for recording user information, and a post-defect that occurs after the start of use. It is divided into a second index area 6 in which data is registered. In the user zone 2, tracks (not shown) are arranged spirally or concentrically, and the circumferential direction of the track is divided into a number of sectors 7a to 7x, and information is recorded for each sector of each track. , Playback, deletion or deletion.

FIG. 6 is an explanatory diagram showing an example of a sector format, in which SM is a sector mark indicating the start position of each of the sectors 7a to 7x, and VFO ₁ and VFO ₂ are recorded in ID ₁ , ID ₂ , and ID ₃ . reference frequency signal portions clock pull signal required to read out the track number and sector number is recorded, AM is an address mark, CRC indicating the start position of the track number is read from the ID _1, ID _2, ID ₃ Information for checking whether an error is included in the data of the track number and the sector number, PA is a postamble indicating the end position of the header part, and the SM-less ID
_{In 3} , predetermined information is recorded in the form of pre-pits.

ODF is a flag area in which no signal is written to detect the offset of the light spot, and Flag is Data F
A flag indicating that information has been written to the ield, ALPC is an area for determining the laser power required for recording / reproducing information, Gap is an empty area set between ODF and Flag, Flag and ALPC, VFO ₃ is a reference frequency signal section in which a clock pull-in signal necessary for reading user information and the like recorded in the data field is recorded, Sync is an area in which information used for synchronizing VFO ₃ is recorded, and Buffer is a buffer area. is there.

On the other hand, the optical disc evaluation device includes a defect detection unit that detects a defect in a recording layer, an error detection unit that detects a recording error, and a recording unit that writes information to an optical disc. After the detection unit is driven to perform the defect detection and the error detection unit, the recording unit is driven to set a defective sector and a sector in which an error has occurred as a bad sector to the first index area 4 or the second index. It is registered in the area 6.

[Problems to be solved by the invention]

Incidentally, if there is a defect in the recording layer, corrosion or the like tends to proceed from there, and the size of the defect may gradually increase with time. For this reason, even if it is initially determined that there is no defect and it is determined that normal information can be recorded / reproduced, an area where a defect or an error occurs later due to the enlargement of the defect.

Since the Data Field has a strong error correction function such as ECC and CRC, even if any defect occurs in the relevant part after recording information in the Data Field, data can be reproduced unless it is a major defect It is. Even if a defect occurs in a part of the header part (the area from SM to PA in FIG. 6), since a plurality of VFOs, AMs, and IDs are recorded for each sector, one of them is recorded.
If one can be read, data can be reproduced without any trouble.

However, if a defect subsequently occurs in the VFO ₃ or Sync area and the information cannot be read even on one side, there is no alternative area and no error correction function, and data reproduction is almost impossible. Will be possible.

Such inconvenience cannot be prevented by the conventional evaluation method of performing defect detection and error detection of the optical disc and registering the sector in which the defect or error has occurred in the index areas 4 and 6. No measures have been taken to prevent the loss of valuable data.

The present invention has been made in order to solve the above-described deficiencies of the related art, and an information recording medium capable of preventing a data reproduction failure due to a temporal expansion of a defect and a method of manufacturing such an information recording medium It is an object of the present invention to provide an information recording medium evaluation device suitable for performing the above.

[Means for solving the problem]

In order to achieve the above object, the present invention divides the circumferential direction of a spirally or concentrically arranged track into a number of sectors and, for each information recording medium, records information on each sector of each track. In an information recording medium having a data area configured so that recording, reproduction, erasing or deletion can be performed, and an index area in which data relating to a bad sector generated in the data area is registered, the index area may have a defect or A predetermined multiplication factor is determined not only for the defective sector in which a signal write or read error has occurred, but also for one or more tracks adjacent to the track including the defective sector, and for the size of the defect or error occurring in the defective sector. And the corresponding sector of the track corresponding to the number of tracks calculated by multiplying by Was the configuration that.

Further, with respect to the information recording medium evaluation device, the circumferential direction of a spirally or concentrically arranged track is divided into a large number of sectors, and information can be recorded, reproduced, erased or deleted for each sector of each track. A data area configured as described above, and an information recording medium having an index area in which data relating to a bad sector generated in the data area is mounted, and a continuous search or sampling search of the track with a light spot is performed. In an information recording medium evaluation device for detecting a defect in the data area and registering the sector including the defect as a defective sector in the index area, not only the defective sector having the defect but also a track adjacent to the track including the defective sector One or a plurality of tracks, the size of a defect or an error occurring in the defective sector. The corresponding sector of the track corresponding to the number of tracks calculated by multiplying the constant growth factors, and the configuration that is registered as a defective sector in the index area.

[Action]

According to the means, recording of normal information without defect /
Even if it is determined that reproduction can be performed, an area in which a defect or an error is likely to occur later due to the expansion of a defect is registered as a defective sector in advance, so that the information storage property is excellent. Information is recorded only in the sector.

Therefore, the inconvenience that the once recorded data cannot be reproduced afterwards is improved, and a highly reliable information recording medium can be provided.

〔Example〕

Hereinafter, an embodiment of the present invention will be described using an evaluation device suitable for an optical disc as an example.

FIG. 1 is an explanatory diagram of an optical disk evaluation device according to the present embodiment. In this figure, 11 is an optical disk, 12 is a laser, 13 is a beam shaping prism, 14 is a collimator lens,
Reference numeral 15 denotes a first polarization beam splitter, and reference numeral 16 denotes an objective lens, which constitutes an incident system of the laser beam 12a to the optical disk 11. 17 is a λ / 2 plate, 18 is a condenser lens, 19 is a second polarizing beam splitter, 20 and 21 are photodetectors, 22
Is an addition amplifier, which together with the objective lens 16 and the first polarizing beam splitter 15, constitutes a reflection system for the laser beam 12a.

23 is a bit counter that counts the number of bits from the sector mark SM, determines a position of a predetermined specific area, for example, VFO ₃ and Sync, and outputs a specific area detection signal d. 25 and 26 are bit counters While the specific area detection signal d is output from 23, a slice level variable device that outputs low-level slice signals e and f, 27 and 2
8 is a defect detector for detecting a defect by comparing the output signal level of the addition amplifier 22 with the output signal level of the slice level variable devices 25 and 26, and 29 is a defect detector for detecting any one of the two defect detectors 27 and 28. This is an OR circuit that outputs a defect signal i when a defect is detected, and constitutes a defect detection system.

Reference numeral 31 denotes a track counter for determining the number of the track on which the defect inspection is being performed, 32 is a sector counter for determining the number of the sector on which the defect inspection is being performed, and 33 is registered as a defective sector when the defect signal 30 is input. A registered sector setting circuit for determining the range and sector of a track to be recorded, a signal generating circuit 34 for generating a signal to be registered in the index area 4 or 6 of the optical disk 11 based on an output signal of the registered sector setting circuit 33, and a reference numeral 35 for the entire apparatus This is a control circuit for controlling and constitutes a registration system for a bad sector.

Next, the operation of the optical disc evaluation apparatus according to the embodiment will be described.

The control circuit 35 controls the intensity of the laser beam 12a emitted from the laser 12 to a defect detection level, and accesses the desired track of the laser beam 12a.

A laser beam 12a emitted from the laser 12 is focused on a desired track of the optical disk 11 via a beam shaping prism 13, a collimator lens 14, a first polarizing beam splitter 15, and an objective lens 16. The laser beam 12a incident on the optical disc 11 is reflected by a recording layer (not shown), and is reflected by an objective lens 16, a first polarizing beam splitter.
The light enters the photodetectors 20 and 21 via the λ / 2 plate 17, the condenser lens 18, and the second polarizing beam splitter 19.

The photodetectors 20 and 21 output electric signals a and b proportional to the intensity of the incident laser beam 12a, and the addition amplifier 22 adds the electric signals a and b output from the photodetectors 20 and 21. And outputs a sum signal c amplified to a predetermined level. If the optical disc 11 has a defect, the photodetectors 20, 2
The intensity of the laser beam 12a incident on 1 decreases or increases. Accordingly, the sum signal c output from the addition amplifier 22 also has an output variation proportional to the size of the defect, as shown in FIG.

The bit counter 23 counts the number of bits from the sector mark SM, and sets a predetermined specific area, for example, VFO ₃
And a position of Sync or the like, and outputs a specific area detection signal d. While the specific area detection signal d is being output from the bit counter 23, the slice level variable units 25 and 26 output low-level slice signals e and f, as shown in FIG. 2 (b). As a result, the defect detection in the specific area is performed more strictly than in other parts.

The defect detectors 27 and 28 compare the output signal level of the addition amplifier 22 with the output signal levels of the slice level variable devices 25 and 26, and determine whether the output signal level of the addition amplifier 22 exceeds the output signal level of the slice level variable devices 25 and 26. When there is an output signal, FIG. 2 (c)
As shown in (1), defect signals g and h are output. OR circuit 29
Outputs a defect signal i when one of the two defect detectors 27 and 28 detects a defect.

The track number and sector number of the defective part are
It is determined by the track counter 31 and the sector counter 32. When the defect signal i is input, the registered sector setting circuit 33 specifies a track in which a defect is found and the sector of one or more tracks adjacent thereto. The number of tracks to be designated can be set arbitrarily. However, the range of corrosion or the like that progresses from a defective portion during the storage life (5 to 50 years) required for an information recording medium is determined by an experiment, It is particularly preferable to set the value so as to include the entire range of For example, when the size of the initial defect is E (the number of tracks) and the ratio of the defect or error that expands during the storage life, that is, the growth coefficient is α,
The range of α × E is registered as a bad sector.

The signal generating circuit 34 generates a signal to be registered in the index area 4 or 6 of the optical disk 11 according to the output signal j of the registered sector setting circuit 33.

The control circuit 35 tracks the objective lens 16 to the index area 4 or 6 of the optical disk 11, raises the output of the laser 12 to a recording level, and writes a track number and a sector number registered as a defective sector.

As a result, the optical disk 11 having excellent information preservability, in which the use of not only defective sectors but also sectors that are likely to cause defects in the future is prohibited, is manufactured.

In the above-described embodiment, the case where the defect inspection of the optical disk is performed and the defective portion and the adjacent area are registered as the defective sector has been described. However, for the optical disk that can be repeatedly erased and rewritten such as a magneto-optical disk, for example, It is also possible to detect the presence or absence of a recording error and register the error occurrence part and its adjacent area as a defective sector.

FIG. 3 is an explanatory view of an optical disk evaluation device provided with such an error detecting means. Reference numeral 41 denotes a write (WR) power adjuster for adjusting the power of a laser beam emitted from the laser 12, and reference numeral 42 denotes an optical disk evaluation device. A WR pattern generator 43 for generating the write pattern k, 43 is a differentiating circuit for differentiating the output signal c of the addition amplifier 22, and 44 is a binarizing circuit for binarizing the differential signal 1
A digitizing circuit, 45 is a comparator for comparing the write pattern k with the binarized signal m, 46 is a device that counts the number of bits from the sector mark SM, and sets a predetermined specific area, for example, a position of a VFO ₃ and Sync. 1, an error position detection circuit 47, an error detection circuit 48 for detecting the presence / absence of an error in a specific area, and other portions corresponding to those in FIG. 1 are denoted by the same reference numerals. .

Hereinafter, the operation of this device will be described with reference to FIGS. 4 (a) to 4 (c).

First, the control circuit 35 accesses the desired track with the laser beam 12a, and writes the signal k generated by the WR pattern generator 42 in a desired sector.

Next, the intensity of the laser beam 12a emitted from the laser 12 is adjusted to the reproduction level by the WR power adjuster 41, and the laser beam 12a is again accessed by the control circuit 35 on the track on which the signal has been written, and is written first. Read the signal.

The read signal is supplied to a differentiating circuit 43 and a binarizing circuit 44.
Is converted into a binary signal m corresponding to the signal pattern k generated by the WR pattern generator 42.

The comparator 45 has a write pattern k shown in FIG.
Is compared with the binarized signal m shown in FIG.
The error detection signal shown in FIG. The error detection circuit 48 detects the presence or absence of an error in a specific area,
If there is an error, an error signal is output.

If an error is detected, the index area 4 or 6 of the optical disc 11 is
Then, the sector in which the error has occurred and the sector in one or more tracks adjacent thereto are registered as bad sectors.

In the above embodiment, the VF is used as the specific area.
O ₃ and have chosen to Sync, but could be identify other region areas.

Further, in the above-described embodiment, the evaluation criterion for the defect in the specific area is stricter than the evaluation criterion for the defect in the other area.

Furthermore, in the above-described embodiment, the optical disk evaluation device has been described as an example, but the present invention can be applied to other information recording medium evaluation devices such as a magnetic disk evaluation device.

Further, in the above-described embodiment, the track is continuously searched by the light spot at the time of the defect inspection or the error detection. However, in order to reduce the measurement time, a specific track selected in advance can be sampled and searched. In this case, taking into account that the defect area or error area usually covers a plurality of tracks, not only the track where the defect or error is detected, but also the corresponding sector of several tracks before and after the track where the defect or error is detected. Can also be registered in the index areas 4 and 6 as bad sectors.

〔The invention's effect〕

As described above, according to the present invention, not only sectors having a defect or an error but also sectors having a high possibility of causing a defect or an error in the future are prohibited. It can be significantly improved.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram showing an example of an information recording medium evaluation device according to the present invention, FIG. 2 is an operation explanatory diagram thereof, and FIG. 3 is an explanatory diagram showing another example of an information recording medium evaluation device according to the present invention. , Fourth
FIG. 5 is an explanatory diagram of the operation, FIG. 5 is an explanatory diagram showing an example of zone division of a conventionally known optical disk, and FIG. 6 is an explanatory diagram showing an example of a sector format of the optical disk. 11 ... optical disc, 12 ... laser, 13 ... beam shaping prism, 14 ... collimator lens, 15 ... first polarizing beam splitter, 16 ... objective lens, 17 ... λ / 2 plate, 18
…… Condenser lens, 19 …… Second polarization beam splitter,
20,21 ... photodetector, 22 ... addition amplifier, 23 ... bit counter, 25,26 ... slice level variable device, 27,28 ...
Defect detector, 29 OR circuit, 31 track counter, 32 sector counter, 33 registered sector setting circuit, 34 signal generation circuit, 35 control circuit.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) G11B 20/12 G11B 20/10

Claims (10)

(57) [Claims] 1. A circumferential direction of a spirally or concentrically arranged track is divided into a large number of sectors, and information can be recorded, reproduced, erased or deleted for each sector of each track. In an information recording medium having a data area and an index area in which data relating to a defective sector generated in the data area is registered, the index area includes not only a defective sector in which a defect or a signal writing or reading error has occurred but also a defective sector. One or more tracks adjacent to the track including the defective sector, the number of tracks corresponding to the number of tracks calculated by multiplying the size of the defect or error generated in the defective sector by a predetermined multiplication factor. An information recording medium, wherein a corresponding sector is registered as a bad sector. 2. The information recording medium according to claim 1, wherein
When a defect occurs afterward and a signal cannot be read out in a specific area in each of the sectors, a defect occurs in an area having no alternative area instead of this and having no error correction function, and the index In the area, a predetermined multiplication factor is determined according to the size of a defect or an error in one or a plurality of tracks adjacent to a defective sector having a defect in the specific area and a track including the defective sector. An information recording medium characterized in that the corresponding sectors of tracks corresponding to the number of tracks calculated by multiplying by (i) are registered as defective sectors. 3. The information recording medium according to claim 2, wherein
An information recording medium, wherein the specific area is a reference frequency signal section and a sync pattern recording section in each sector. 4. The information recording medium according to claim 1,
The information recording medium according to claim 1, wherein the proliferation coefficient is a function of a storage age of the information recording medium. 5. A spiral or concentrically arranged track is divided into a number of sectors in a circumferential direction, and information can be recorded, reproduced, erased or deleted for each sector of each track. A data area and an information recording medium having an index area in which data relating to a bad sector generated in the data area is registered are mounted, and the track is continuously searched or sampled by an optical spot, and the track is searched for in the data area. In an information recording medium evaluation device that detects a defect and registers a sector including the defect as a defective sector in the index area, the information recording medium evaluation device includes not only a defective sector having the defect but also one or more tracks adjacent to a track including the defective sector. Multiplying a size of a defect or an error caused in the bad sector by a predetermined multiplication factor; The corresponding sector of the track corresponding to the number of tracks that are more calculated, the information recording medium evaluating apparatus characterized by registered as a defective sector in the index area. 6. The information recording medium evaluation apparatus according to claim 5, wherein a specific area in each of the sectors is replaced by a substitute area which is replaced by a defect if a signal cannot be read after a defect occurs. If there is a defect in an area that has no error correction function and there is a defect in the specific area and one or more tracks adjacent to the track containing the defective sector, An information recording medium evaluation device for registering, as a bad sector, a corresponding sector of a track corresponding to the number of tracks calculated by multiplying the size of the generated defect or error by a predetermined multiplication factor. . 7. The information recording medium evaluation apparatus according to claim 6, wherein the specific area is a reference frequency signal section and a sync pattern recording section in each sector. 8. The information recording medium evaluation device according to claim 5, wherein the evaluation criterion of the defect in the specific area is stricter than the evaluation criterion of the defect in the other area. . 9. The information recording medium evaluation device according to claim 5, wherein recording means for writing a signal to said data area;
An information recording medium evaluation device, comprising: a reproducing unit for reading a signal recorded in the data area; and a comparator for checking a pattern of a write signal and a read signal. 10. The information recording medium evaluation device according to claim 5, wherein the information recording medium is an optical disk or a magnetic disk.